A website's relevant value as determined by the Google search engine. The more "juice" a site has, the more likely it will turn up in search results. This is especially true when the search terms aren't the title of that site.

Google's particular method, known as PageRank, determines this importance according to who links what. If a high-ranking site links to a low-ranking one, that site will be given lots of juice. If a low-ranking site links to something, it doesn't have as much relevance. The text of the link also is taken into account.